Well surveying apparatus



July 22, 1958 J. K. STORY WELL SURVEYING APPARATUS 5 Sheets-Sheet 1 Filed Oct. 28, 1954 a A. 6 4 a 4 0 ,2 fl 2 "a M a 5 m fl/ w m w. 0. A A J nwfiv am umfi W W K a A A Q 5 L a H w 7 M. lvpa. J W. 7 8 8 T a a a M, 2 I 7 1 \v n M M July 22, 1958 J. K. STORY WELL SURVEYING APPARATUS 5 Sheets-Sheet 2 Filed Oct. 28, 1954 INVENTOR. MES K $70214 ZZ F w flrrakwe u July 22, 1958 J. K. STORY WELL SURVEYING APPARATUS Filed Oct. 28, 1954 5 Sheets-Sheet 3 [\qhi Condudor I 1 nbk 1/ l sa fizz-z I I a; w; y?

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United States Patent OfiT- ice 2,843,941 Patented July 22, 1958 WELL SURVEYING APPARATUS James K. Story, Long Beach, Calif., assignor to V. E. Kuster, Long Beach, Calif.

This invention relates to improved apparatus for performing a survey of a well bore to accurately determine the extent to which the bore has deviated from a true vertical course.

In the types of well surveying equipment heretofore used, the apparatus employed has only been capable of partially completing a survey, specifically, by merely indicating or recording the inclination readings at a number of spaced locations in a well, and those readings then had to be interpreted or translated by the operator into a readily intelligible form by a rather tedious calculation process. A major object of the present invention is to provide surveying apparatus which does considerably more than merely take inclination and direction readings, and in particular which itself places the well information in a very easily interpreted form. Preferably, the apparatus is entirely automatic and serves by itself to completely calculate the survey. More specifically, the equipment may function tocompute directly the various vertical and horizontal components of the distance travelled (or course length) between a pair of successive stations, those components comprising (1) the vertical distance between the levels of the two stations (2) and north-south horizontal digression of the bore between stations, and (3) the east-west digression of the bore between stations. As for its general manner of operation the equipment may operate automatically to first advance or lower a survey instrument from one station to another, then record or compute the survey information for the distance or course length between those stations, next advance the instrument to another station,

then compute the information for the second course length, etc., until the entire bore has been surveyed.

In order to accomplish these results, the apparatus should include a first pick-up unit for responding to the inclination of the instrument, and desirably also the direction of that indication, and a second unit for responding to advancement of the instrument in the well.

A computer may then be provided which takes the information from both of these units and computes from it one or more of the specified components of a particu- Preferably, this is performed by multiplying the course length (usually electronically) by a proper trigonometric function of the inclination or deviation angle, to arrive at the horizontal and/or vertical distance between stations. For instance, the course length between two stations may be multiplied separately by both the cosine and sine of the angle of deviation to give both the vertical and horizontal digressions. The horizontal digression may then be multiplied separately by both the sine and cosine of an angle representing the compass direction of the deviation, to determine both the north-south and east-west components of the horizontal digression. To elfect such multiplications, I may use sine-cosine resolvers or generators, having potentiometers actuable to develop electrical potentials proportional to the sine and/ or cosine of an angle, and which 2 potentiometers are connected into suitable multiplier circuits.

The inclination pick-up portion of the instrument may include two inclination responsive devices, typically variable resistor devices, adapted to respond to the inclination of the instrument in two different planes, and whose outputs are added in a vector like fashion to arrive at the true inclination. For adding these outputs, I may employ a resolver having two essentially perpendicular screws which actuate a common element in two different directions, with the positioning of the element being read out by a pair of otentiometers actuable thereby. In conjunction with the two ofiset inclination responsive devices, I may employ a compass element which is responsive to the rotary positioning of the two devices in a well, and whose output may be utilized to orient the outputs of the devices and thereby determine the true direction of the inclination.

Certain particular features of the invention involve the utilization of a unique type of follow-up system in the instrument, for actuating a resistor or other control element in accordance with rotation of the compass element. As will appear, it is contemplated that this followup system may in certain instances, also be utilized in other types of well instruments, adapted to respond to temperature, pressure or other conditions rather than compass indications. Specifically, the follow-up system comprises a first light polarized lens movable with the compass element (or the temperature or pressure response element), and a second polarized lens mounted in light passing alinement with the first. Light is directed through these two lenses and falls on light sensitive control means acting to control movement of the second lens in a manner causing it to follow the first. The output resistor may then be connected to the follower lens for actuation in accordance with movements thereof.

The above and other features and objects of the present invention will be better understood from the following detailed description of the typical embodiments illustrated in the accompanying drawings, in which:

Fig. l is a partially schematic view showing a well surveying unit constructed in accordance with the present invention;

Figs. 2a and 2b are vertical sections taken on line 2-2 of Fig. 1 through the surveying instrument which is lowered into the well, Fig. 212 being a lower continuation of Fig. 2a;

Figs. 3, 4 and 5 are enlarged horizontal sections taken on lines 3-3, 4-4 and 5-5 respectively of Fig; 2b;

Fig. 6 is a schematic representation of the working parts and electrical circuit of the instrument shown in Figs. 2a and 2b;

Fig. 7 is a circuit diagram of the computer, showing the manner in which the computer is connected to and controlled by various other portions of the apparatus;

Fig. 8 is a diagram representing the well surveying problem which is to be solved by the illustrated apparatus;

Fig. 9 is an enlarged plan view of the portion of the computer which acts to compute the well bore inclination, and the direction of the inclination, from the information obtained by the instrument in the well;

Fig. 10 is a fragmentary view taken on line 10-10 of Fig. 9;

Fig. 11 is a side view of a sine-cosine resolver which is utilized in the computer;

Fig. 12 is a fragmentary view taken on line 12-12 of Fig. 11;

Fig. 13 is a somewhat schematic representation of a quadrant indicating assembly, which is driven by the resolver of Fig. 11;

Fig. 14 is a -fragmentary schematic representation of a variational form of instrument, which is similar to the instruments shown in Figs. 2a and 211, but is utilized for indicating pressure changes in the well rather than inclination or direction changes; and

15 is another variational form of instrument which in this case is utilized'for indicating temperature changes in the well.

Referring first to Fig. 1, I have shown at a well bore which is to be surveyed to determine whether it has deviated from a true vertical course, and if so to what extent it has deviated. The apparatus for conducting this survey includes a vertically elongated surveying instrument 11 which is lowered into the well on a flexible eight conductor cable or wire line 12, the instrument being lowered or raised by motor driven rotation of a drum 13 about which the wire line 12 is wound at the surface of the earth. Between drum 13 and the instrument, wire line, 12 passes about a second drum 14, whose rotation is utilized for communicating to a computer 15 at the surface of the earth a signal representing the distance that the instrument has been lowered between two successive stations or locations. The motor for driving drum 13 is typically represented in the drawings at 16.

The instrument 11 contains three variable resistors 17, 18 and 19, which are electrically connected to the computer 15 by means of the eight conductor cable 12. The two .uppermost variable resistors 17 and 18 are actuated in accordancewith the inclination of instrument 11 in two different circularly offset and perpendicular planes. The computer 15 acts among other things to vectorially add together these two inclinations, to arrive at their vectorial sum. The third resistor 19 is controlled by a compass unit 21 within the instrument, to communicate to computer 15 the rotary positioning of the body of instrument 11 within the well bore. The computer then utilizes this directional signal from compasscontrolled resistor 19 to orient the inclination obtained from resistors 17 and 18, and thereby determine the true direction of inclination of the well bore.

After the inclination and its compass direction have thus been derived by computer 15, the computer proceeds to combine this information with the information obtained from drum 14 as to the distance through which instrument 11 is moved within the well bore. This combined information is utilized by the computer to show on an indicator board 22 four things, specifically, the vertical distance through which instrument 11 is moved between two different stations in the Well (as distinguished from the angular course length indicated by drum 14) the east-west digression or departure 24 of the bore hole between those stations, the north-south digression 25 of the bore hole between those stations (sometimes called latitude), and the total course length 125 at each station. A camera 26 may be included in the computer for photographing indicator board 22 at a series of successive stations or vertically offset locations within the well bore, to provide a record of an entire well survey.

Referring now to Figs. 2a. and 2b, the instrument 11 which is lowered into the well comprises a vertically elongated rigid instrument body or housing 27, which may be formed of a number of detachable sections threadedly interconnected at joints 28. All of the later to be described parts of instrument 11 are contained within body 27, and are effectively sealed against contact with the well fluid at the outside of the body. To thus seal the body, there may be provided about its threadedly interconnected sections an outer tubular fluid tight jacket 29, whose lower end may form a bottom nose 30 of the instrument, and Whoseupper end31 may be annularly sealed to the uppersectionof the body, as by a suitable annular seal ring 32. Jacket 29 is of course strongenough to with- 4- stand the very high pressures encountered at the bottom of most wells.

The tWo inclination responsive variable resistors 17 and 18 (see Fig. 2a) are contained within two vertically and circularly offset recesses 33 and 34 formed in the side of an upper section of body 27. Each of these resistors is arcuately disposed about a horizontal axis 35, and is preferably essentially semicircular. A movable con tact 36 swings about axis 35 to engage resistor 17 (or 18), and thus vary its effective resistance in accordance with positioning of contact 36. This contact is carried by a plumb bob element 37, which also swings about axis 35, and has a lower Weight portion 38 which at all inclinations of the instrument swings to as nearly a vertical position as is permitted by the mounting of the plumb bob. It will thus be apparent that the resistance of element 17 corresponds to the inclination of instrument 11 in the plane within which plumb bob 37 swings. The axis of resistor 18 and its plumb bob is offset about the vertical axis of the instrument with respect to the axis of resistor 17 and its plumb bob, so that the resistance of element 18 corresponds to the instrument inclination in a plane perpendicular to the plane represented by resistor 17. Each of these resistors and its plumb bob may be contained within a body of oil, to lubricate the parts and to dampen the plumb bobs movements. At a later point, it will be brought out just how computer 15 vectorially adds the readings of circularly offset resistors 17 and 18.

Compass unit 21 is of the meniscus centered type, including a housing containing a body of liquid 40 Which movably supports an essentially cup-shaped compass float 41. Container 21 has a tubular projection extending downwardly from its upper wall to a location within the upper annular portion of float 41. The body of liquid 40 forms an annular meniscus 43 between the proximate surfaces of float 41 and projection 42, which meniscus serves as a low friction buffer between the float and projection, acting to effectively center the float and guide it for rotation about a vertical axis. At the same time, this meniscus allows the float to swing to an angular position relative to projection 42 when the instrument is inclined within a well. About a lower portion of float 41, there is provided an annular magnetized compass ring 44, which is maintained in a predetermined rotary position by the earths magnetic field. Rotation of the ring of course carries with it the entire float 41.

Resistor 19 is positioned above compass unit 21 within the instrument body, and includes a movable contact which is rotatable about the axis of the instrument through 360, and which progressively varies the resistance of element 19 through the entire range of movement. Re-

sistor 19 is caused to exactly follow the rotation of compass float 41 by means of a follow-up system including a motor 45 acting through a reduction gear assembly 146 and vertical shaft 147. This follow-up system is controlled by two photoelectric cells 46 and 47, to which light passes upwardly from a light bulb 48 located near the bottom of the instrument. The light from bulb 48, before it reaches cells 46 and 47, passes through two polarized lenses or discs 49 and 50, the first of which forms a bottom wall of compass float 41, and the second of which is connected by shaft 51 to the movable contact of resistor 19, to turn with the resistor and its drive shaft 147. Suitable focusing lenses 52, 53 and 54 may be provided for directing the light along its upward course of travel first through disc 49 and then through the somewhat larger disc 50. Also, the container must of course be designed to pass light upwardly therethrough, as by providing a glass bottom wall portion 55 on the container.

The compass carried disc 49 is polarized over its entire area in one predetermined horizontal direction, while the upper disc 50 is formed of two differently polarized por tions. Specifically, the inner circular portion 56 of disc 50 may be polarized in a first horizontal direction, while an sateen outer annular portion 57 of this disc is polarized in a horizontal direction which is directly perpendicular to the direction of polarization of poriion 56. Some of the polarized light passing upwardly from compass disc 49 passes through the outer portion 57 of disc 50 into a passage 58 in the body, and is reflected by an angular mirror surface 59 onto a first of the photoelectric cells 46. Some of the rest of the polarized light from disc 49 passes through the central portion 56 of disc 50 and then through a second passage 60 for reflection by a second mirror surface 61 onto the second photoelectric cell 47. The two mirror surfaces 59 and 61 may be formed as lower angular faces on a pair of plugs 62 which are connected into upper continuations of the vertical portions of passages 58 and 60.

As will be understood, if the polarized compass disc 49 turns relative to polarized disc 50, this relative rotation will cause the amount of light passing through one of the two portions 56 and 57 of disc 50 to increase, and the amount of light passing through the other portion of that disc to decrease. The resultant changes in the light energization of photoelectric cells 46 and 47 are utilized to cause motor 45 to rotate disc 50 (and thereby resistor 19) in a direction to return disc 50 to its original position relative to disc 49. In this manner, resistor 19 is always maintained in a position corresponding to the rotary position of compass element 49.

The electric circuit by which photoelectric cells 46 and 47 control follow-up motor 45 is shown in Fig. 6. Power is supplied to this circuit from a source 162 at the surface of the earth (see Fig. 7), through a pair of leads 63 and 63a, under the control of a main on-off switch 72 (also located at the surface of the earth), the power source typically being 120 volts A. C. 60 cycle. The lead 63 may be one of the eight conductors of cable 12, while the lead 63a may be connected to the power source by grounding, typically through a steel load supporting covering on cable 12. Across this power source is connected the primary coil of a step-down transformer 64, whose secondary voltage may be 6.3 volts. One side of the primary coil is connected to a side of the secondary coil by means of a connection 65, and in a relation such that the primary and secondary voltages add together in the resulting series circuit which includes both the primary and secondary coils. That is, the two coils are so interconnected that, if the primary voltage is 120 volts and the secondary voltage is 6.3 volts, the potential dilference between the points 193 and 194 in Fig. 6 is 126.3 volts (120 plus 6.3).

The two photoelectric cells 46 and 47 are utilized to control the firing of two electron tubes 195 and 196 respectively, which tubes may typically be of the type designated 2D21. The cathode heaters of these tubes are connected to and energized by the secondary coil of transformer 64. The anodes of the two photoelectric cells 46 and 47 are connected in parallel to the side 193 of the primary coil of. transformer 64. The cathodes of the two photoelectric cells 46 and 47 are connected in parallel to the side 193 of the primary coil of. transformer 64. The cathodes of the two photoelectric cells are connected separately to the movable contacts of a pair of potentiometers of voltage dividers 197 and 198, whose resistor elements are connected in parallel to the second-.

ary side of transformer 64. The main grid of each tube 195 and 196 is connected into the line leading from the cathode of the corresponding photoelectric cell, and the associated potentiometers 197 and 198, with an additional resistor 199 or 200 being connected into that line at a location between the grid connection and the potentiometer. The cathodes of tubes 195 and 196 are connected to the line 65 joining the two transformer coils, preferably by grounding both the cathodes. and line 65.

The plate circuits of the two tubes 195 and 196 include the primary coil of an output transformer 201, which coil is center tapped at 202. The two tube plates are connected to opposite ends of the primary coil of this transformer, and the center tap 202 is connected through a time delay switch 203 to the side 193 of the primary coil of transformer 64. Thus, when one of the two tubes 195 or 196 fires, current flows through onehalf of the primary coil of transformer 201 in a first direction, to induce in the secondary of the transformer a voltage in a first direction, while firing of the other tube causes current to flow through the other half of the transformer primary in a reverse direction, with resultant development of a reverse potential across the secondary of the transformer. Such firing of the tubes is controlled by photoelectric cells 46 and 47, since these cells are connected to the control grids of tubes 195 and 196. In this connection, it is noted that the tubes can fire only during one-half of the cycle of the alternating current power supply, that is, during that half of the cycle in which the tube plates are positive and the tube cathodes are negative. During that half of the cycle, a negative grid bias is provided to the tubes by virtue of the connection of the grid circuits to the secondary of transformer 64 through potentiometers 197 and 198.

The secondary coil of transformer 201 is connected to one of the two coils 204 of a drag cup-type of motor, with this circuit typically including a condenser 305 for properly phasing the current in coil 204 relative to the current in a secondary offset motor coil 205 which is connected directly to the volt power source. As will be understood, current flowing in one direction through motor coil 204 turns the armature 206 ofthe motor in one direction, while a reverse current in coil 204 turns the motor armature in a reverse direction, the direction of rotation in each case being such as to turn polarized disc 50 in a direction to follow the compass float. The time delay switch 203 is of a normally open type, which is adapted to remain open for a predetermined interval after closure of the main switch 72, and which then automatically closes after that interval (say about 10 seconds), to protect the tubes by maintaining the plate circuits open until the cathode heaters have had time enough to warm up.

To now describe in more detail the manner in which the follow-up system of Fig. 6 functions, assume first that the compass carried polarized disc 49 and the follower disc 50 are initially in their predetermined normal relative positions, to which normal relative positions they always tend to return following rotary movement of the compass element. In these normal positions, the direction of polarization of compass carried disc 49 may be disposed at about 45 to the directions of polarization of both of the portions 56 and 57 of follower disc 50. In this condition, the light which passes upwardly through the two polarized discs and then to photoelectric cells 46 and 47 is balanced for the two cells, so that the currents flowing in the plate circuits of the tubes and 196 controlled by the photoelectric cells are equal, with the resultant development of two equal but opposed potentials in the secondary coil of transformer 201, so that no current flows in coil 204 of motor 45, and consequently there is no tendency for that motor to turn disc 50 and the movable contact of resistor element 19.

If the body of instrument 11 then turns within the well, causing resultant rotation of the compass float 41 relative to disc 50, such rotation moves the polarized compass carried disc 49 toward a position of light passing alinement with one of the portions 56 or 57 of disc 50 and farther away from a position of light passing alinement with the other portion of that disc. As a result, the amount of light falling on one of the two photoelectric cells 46 or 47 increases, while the amount of light falling on the other cell decreases. The increased light falling on one cell, say cell 46, causes current to flow in the circuit of that cell, making the potential at the grid of tube 195 more positve to allow an increased amount of current to flow in the plate circuit of the two, thus setting up a flow of current in the secondary coil of transformer 201 and motor coil 204. This causes the motor to turn in a proper direction for returning disc 50 to its original position relative to the compass float, at which position the two photoelectric cell circuits and the two controlled tube circuits are again balanced, to stop the rotation of the motor. If the original rotation of the compass element had been in a reverse direction, the other cell and other tube would have been energized, to cause reverse rotation of the motor, again until the motor had returned disc 50 to the predetermined normal position relative to the compass float. Thus, the effective resistance of resistor element 19 is automatically maintained proportional to the rotary positioning of the compass float relative to the body of instrument 11 (that is, the resistance of element 19 is proportional to the angle by which the compass float is circularly offset from an initial predetermined position relative to the body of the instrument). It will of course be understood that, in the follow-up circuit of Fig. 6, the potentiometers 197 and 198 may be adjusted to provide a proper bias voltage on tubes 195 and 196, for effecting the desired firing of the tubes in response to light energization of the photoelectric cells. These potentiometers may be adjusted either to normally provide bucking and equal plate currents, as discussed above, or to provide no plate currents until the compass float is displaced slightly in one direction or the other from its normal position relative to disc 50. justed as to cause the tubes to immediately fire upon such movement of the compass float relative to disc 59.

For initially orienting polarized disc 50 relative to compass carriedpolarized disc 49 at the beginning of a survey, I provide an electromagnetic coil 66 in the body at one side of the compass container 21, and adjacent magnetized compass ring 44 of the float. When this coil is energized by battery 67, the coil causes compass element 44 and the associated float to turn to a predetermined rotary position relative to the body. Connected into the same circuit with battery 67 and coil 66 is an orienting light 68, which directs light onto photoelectric cell 47, so that the photoelectric cell causes motor 45' to continuously turn disc 50 and resistor 19 in a predetermined rotary direction. This rotation continues until it is stopped by engagement of a lug 69 carried by shaft 147 with the plunger of a solenoid 70. Thus, both the compass element 44 and disc 50 are turned to predetermined positions within the body when the circuit to orienting coil 66 and light 68 is closed, to thereby bring the compass element and disc 50 into an initial properly oriented relation.

The delivery of power to coil 66, light 68 and solenoid 7%) is controlled by a time delay switch 71, which closes for a predetermined short interval, say about 30 seconds, upon closure of the main power supply switch 72, and which then automatically opens and remains open after that interval. Of course, the interval must be sutficient to assure proper orientation of the parts, as described. Deenergization of solenoid 70 by the opening of switch 71 causes the spring urged plunger of solenoid 70 to retract out of the path of lug 69, so that the plunger no longer interferes with free rotary movement of compass element 44 and disc 50.

Before proceeding with a description of the computer, it would be best to briefly describe the problem which it is designed to solve. Referring now to Fig. 8, I have there represented at a the course which an inclined well bore follows between two spaced locations which are designated station 1 and station 2. The uppermost of these stations may be at the surface of the earth, or both stations may be well below the surface of the earth. The object of the survey is to obtain the following three pieces of information as to the digression of the bore hole between station 1 and station 2:

In this latter case, the grid biases are so ad-' (1) The vertical distance c between station 1 and the level of station 2;

(2) The north-south digression d (latitude) of the bore hole between the two stations; and

(3) The east-west digression e of the bore hole between the two stations (departure).

To determine these three factors from the information supplied by instrument 11 and movement measuring drum 14, the computer serves first to combine the readings of the three resistors 17, 18 and 19 in the instrument, to produce representations of the angle of deviation A of the course from the true vertical, and the angle A indicating the compass direction in which the course deviates. After obtaining indications of these two angles A and A the computer then proceeds to electro-mechanically multiply the course length a by the cosine of the angle A to determine the vertical distance between the levels of stations 1 and 2. Also, the computer multiplies the course length a by the sine of angle A to determine the length of a straight horizontal line b which completes a right triangle with course line a and vertical line 0. The resultant length of line b is then multiplied by the sine of angle A to arrive at the east-west digression e, and by the cosine of angle A to arrive at the northsouth digression d.

Fig. 7 shows a preferred circuit diagram for the computer 15. In this diagram, the eight conductor cable leading upwardly within the well is shown at the location of the dotted line 73. The three resistors 17, 18 and 19 of instrument 11 are connected to individual Wheatstone bridge type circuits 74, 75 and 76, which are energized by a battery 7'7, and which cause three motors 1M, 2M and 3M to rotate in correspondence with the rotary motion of the three resistors respectively. Describing specifically the first of these bridge circuits 74, this circuit includes four resistors 78, 79, and 81 connected in series to variable instrument resistor 17. The two resistors 78 and 80 have movable contacts 82 and 83, which are driven in unison by rotation of motor 1M, as indicated by the broken lines 84. An amplifier is connectable into circuit 74 at 85, one side of the amplifier being connected to movable contact 82, and the other side of the amplifier being connected to a point between resistors- 17 and 81. The amplifier then serves to amplify the output from circuit '74, with the output of the amplifier being utilized to drive motor 1M. The amplifier and motor 1M are so designed that any power flowing to the amplifier from the bridge circuit and then to the motor, causes the motor to turn in a direction such as to actuate movable contacts 82 and 83 in unison either to the left or to the right (depending upon the direction of the current flowing to the amplifier), and to a position at which current ceases to flow to the amplifier and motor. Thus, any change in the resistance of element 17, resulting from a change in inclination of the well bore and instrument 11, causes the bridge-circuit 74 to become unbalanced, resulting in delivery of power to the amplifier and motor 1M, which power actuates the movable contacts in a direction to again balance the Wheatstone bridge circuit and cease the delivery of power to the amplifier and motor. There is thus set up a null balance system, which causes motor 1M to follow the movement of contact 36 of inclination responsive resistor 17. That is, if contact 36 swings in one direction, motor 1M rotates in a corresponding direction and through a proportional distance (though motor 1M turns several times for only a portion of a revolution of contact 36) while reverse movement of contact 36 causes a corresponding reverse rotation of motor 1M. The two other Wheatstone bridge circuits 75 and 76 are the same as circuits 74, and cause rotation of motors 2M and 3M in correspondence with actuation of the movable contacts of resistors 18 and 19 respectively. In order to simplify the construction of the computer, a single amplifier may be utilized for all three of the Wheatstone bridge circuits 74, 75' and 76, as well as for various other circuits to be described later, with this single amplifier being successively connected into the various circuits at the locations designated in broken lines Ampifier 1, Amplifier 2 and Amplifier 3.

The driven shafts of motors 1M, 2M and 3M are mechanically connected to a resolving device 86, which combines the readings taken from these motors to develop from them the two critical angles A (deviation) and A (compass direction of deviation). The output of resolver 86 is utilized to rotate motors 4M and 5M to positions corresponding to angles A and A respectively. The mechanical output of motor 4M is then utilized to drive a potentiometer 87, which is connected into a multiplier circuit 88 acting to multiply the course length by the cosine of angle A to give the vertical depth at 23. A second multiplier circuit 89 multiplies the course length by the sine of angle A to rotate motor 7M to a position corresponding to the length of line b in Fig. 8, following which the length of that line as represented by the actuation of motor 7M is multiplied separately by the cosine and sine respectively of angle A by means of circuits 90 and 91, to position motors 8M and 9M in correspondence with the north-south and east-west digression of the bore hole.

The resolving device 86 includes two parallel laterally spaced elongated rotary screws 92, which are suitably mounted for rotation about their individual parallel axes, as by bearings 93. One of the screw elements is mechanically driven by motor 2M, as through a connection including a pair of bevel gears 94. The second of the screw elements 92 is rotatably driven in unison with the first, as for instance by providing a pair of gears 95 on the two screw elements, with an intermediate power transmitting gear 96, mounted by bearings 97, meshing with and transmitting power between the two gears 95.

A third screw element 98 extends perpendicularly to and between screws 92, and is rotatably journalled within a pair of bearing blocks 99 carried by the two screws. Each of these bearing blocks contains a threaded bore through which the corresponding screw extends, so that rotation of screws 92 in unison acts to displace blocks 99 and their rotatably carried screw 98 axially relative to screws 92. The third screw 98 is driven by motor 1M, typically through a flexible drive connection 100 and a pair of bevel gears 101. Screw 98 threadedly carries a nut element or block 102, which is actuated axially along screw 98 in accordance with rotation of that screw. A guide rod 98a, rigidly carried by and extending between blocks 99, extends through a guide opening in block 102 to slidably guide that block for only axial movement, and thereby prevent rotary movement of block 102 with screw 98. Block 102 is pivotally connected at 103 to an extensible potentiometer unit 104, which swings about its axis 105 in accordance with movement of block 102. As will be understood, in the resolving device of Fig. 9, motor 1M causes block 102 to be displaced axially of screw 98 in accordance with the inclination of the tool 11 in the plane of resistor element 17, while motor 2M actuates block 102 in the directon of screws 92 and in correspondence with the inclination of tool 11 in the plane of resistor 18. Consequently, the positioning of block 102 with respect to axis 105, by the motors and screws, represents a vectorial summation of the two inclinations read out by resistors 17 and 18.

The angle of deviation A is represented by the distance from axis 105 to block 102, and is obtained in electrical form by means of a linear motion and linear winding potentiometer 106 forming a portion of unit 104. This potentiometer includes an elongated body member 107, which carries a longitudinally extending resistor coil 108, along which a movable contact 109 is slidable. Contact 109 is carried by an elongated arm 110, which is journalled by guide or bushing members 111 for only longitudinal sliding movement relative to body 107, and

which is attached by the pivotal connection 103 to block 102. Body 107 of the linear motion potentiometer is mounted for swinging movement about axis 105, as by a vertical shaft 112 journalled by bearing 113 for rotation about that axis. The lower portion of shaft 112 may be oifset horizontally in the direction of body 107 as at 114, and to an extent allowing movement of block 102 to the center point when necessary. Elongated element carrying movable contact 109 of course intersects axis 105, with the lower ofIset portion 114 of shaft 112 being provided with a suitable opening 115 for slidalbly passing element 110.

For responding to the rotary positioning of block 102 and unit 104 about axis 105, there is provided above bearing 113 a 360 rotary motion linear winding potentiometer 116, whose movable contact 117 is carried by shaft 112 and therefore rotates in accordance with that shaft as determined by the rotary positioning of block 102 about axis 105. Movable contact 117 engages a 360 circular resistor element 118, which is carried by a body 119 which is itself suitably mounted by bearings (not shown) for independent rotation about axis 105. Body 119 has an outertoothed gear-like portion 120, which meshes with a gear 121 driven by motor 3M. The gearing is such as to rotate body 119 exactly in correspondence with, and in a one to one ratio with the rotation of, compass element 44 relative to the body of instrument 11. Consequently, the compass controlled rotation of outer resistor element 118 of the rotary potentiometer 116 acts to vary the reading of potentiometer 116 in correspondence with the rotary positioning of the instrument 11 within a well, to thus cause potentiometer 116 to in all cases actually represent the compass direction of inclination or deviation of the well bore at a particular location. From the above, it will be apparent that the positioning of pointer 109 on linear potentiometer 106 represents accurately the angle of deviation A while the positioning of pointer 117 along the resistor element of potentiometer 116 accurately represents the compass direction in which the bore hole deviates. The readings of these two potentiometers are then utilized to actuate motors 4M and 5M respectively to positions also representing these two angles, with the motor control being effected by a null balance system. For instance, in the case of potentiometer 106, the resistance element 108 is connected to a battery 122 in parallel with the resistance element of a second potentiometer 123. The movable contacts of these two potentiometers are connected to an amplifier amp. 4, whose output is utilized to drive motor 4M. Motor 4M in turn is mechanically connected to the movable contact of potentiometer 123, to actuate that potentiometer in accordance with rotation in either direction of the motor. Motor 4M always returns the movable contact of potentiometer 123 to a position corresponding to the contact of potentiometer 106, so that there is no difference in potential between these two movable contacts, and as a result no current flows to the amplifier and motor 4M. If contact 109 is moved from such a balanced position, a difference of potential is developed between the two movable contacts of potentiometers 106 and 123, causing current to flow to the amplifier and motor in a direction for driving the motor and thereby the movable contact of potentiometer 123 in correspondence with the movement of contact 109 along its resistor. This movement continues until there is again no difference in potential between the two movable contacts.

The read-out circuit 124 between potentiometer 116 and motor 5M includes a read-out potentiometer 125 and a power source 126 serving the same functions as elements 123 and 122 of the read-out circuit for motor 4M. Consequently, it is of course unnecessary to describe the functioning of read-out circuit 124 as specifically as the circuit associated with motor 4M.

; Multiplier circuit 88 includes the previously mentioned potentiometer 87 (linear motion, linear winding) whose movable contact is actuated by motor 4M, and an additional potentiometer 127 which is mechanically driven by drum 14. The resistance element of this latter potentiometer is connected in series with a resistor 128 to the power supply, with the movable contact of potentiometer 127 being connected to one end of the resistor element of potentiometer 87. The other end of the resistor element of potentiometer 37 is connected to the positive side of the power source. This arrangement serves to electrically multiply the setting of potentiometer 127 by the setting of potentiometer 87 (ignoring resistor 128 for the moment), with the result being indicated by the difference in po tential between the movable contact of potentiometer 87 and the positive side of the power source. Since potentiometer 127 is mechanically driven by drum 14, which turns in correspondence with advancement of the instrument carrying wire 12, the setting of potentiometer 127 represents the distance that the instrument is advanced along the bore between stations 1 and 2 of Fig. 8. As will be discussed later, the mechanical drive between motor 4M (whose setting represents angle A and potentiometer 87 is designed to set potentiometer 87 in correspondence with the cosine of angle A rather than in correspondence with the angle itself. As a result, the multiplier circuit serves to multiply the course length a (setting of potentiometer 127) by the cosine of angle A so that the potential difference v between the movable contact of potentiometer 87 and the positive side of the power source represents the vertical distance in Fig. 8 (c=a cosine A In actual practice, I prefer to utilize a particular type of cosine generator (shown at 159 in Figs. 11 and 12), for effecting the mechanical drive between motor 4M and potentiometer 87. This generator acts to move the contact of potentiometer 87 to positions proportional to two times the cosine of angle A and therefore proportional to the cosine itself. In order to minimize the error introduced in multiplier circuit 88, the resistance of potentiometer 87 should be many times as great as the resistance of potentiometer 127, preferably as many as 200 times.

In order to obtain a mechanical indication correspond ing to the potential v in circuit 88, that is, the potential representing the product of the desired multiplication, 1 utilize a read-out potentiometer 153 which acts through a null balance system to cause motor 6M to turn in accordance with movements of the movable contact of potentiometer 87. For this purpose, the resistance element of potentiometer 129 is connected in series with a resistor 130 to the power source, with the movable contacts of potentiometers 8'7 and 153 being connected to the input side of amplifier 6. This amplifier in turn energizes motor 6M, which operates the movable contact of read out potentiometer 153 in accordance with operation of the motor. Thus, if the potential 1 varies, a difference in potential is set up between the two movable contacts of potentiometers 87 and 153, which difference in potential acts through amplifier 6 to drive motor 6M in a direction moving the movable contact of potentiometer 153 to a position in which there is no potential difiference between the two movable contacts. Thus, the positioning of the shaft of motor 6M corresponds exactly to variations in the potential v, and therefore represents exactly the vertical distance 0 in Fig. 8. Motor GM is consequently directly mechanically connected to an indicator at 23, which directly indicates on board 22 the vertical distance 0 between two stations.

Circuit 89 is substantially the same as circuit 88 except that the mechanical connection between motor 4M and potentiometer 129 comprises a sine generator, rather than a cosine generator to actuate the movable contact of potentiometer 129 in accordance with two times the sine of angle A rather than the cosine. As a result, circuit 89 serves to multiply the course length c in Fig. 8 by the sine of angle A so that read-out motor 7M is ro tated to positions corresponding to the length of line b in Fig. 8 (12:4: cosine A A preferred type of sinecosine generator, for forming the mechanical drive between motor 4M and potentiometers 87 and 129, is illustrated somewhat schematically in Figs. 11 and 12. This generator may include two gears 131 and 132, which are individually mounted for rotation about parallel axes 133 and 134, and whose teeth mesh at 142 to interconnect the gears for rotation in correspondence but reversely. The previously mentioned potentiometer 87 comprises an elongated linear potentiometer unit which is connected to and extends between the two gears 131 and 132, to be actuated in accordance with rotation of the gears. This potentiometer is essentially the same as the previously described potentiometer 106, and comprises a body 136 carrying an elongated resistor element 137. An elongated element 138 is mounted for only sliding movement relative to body 136, and has a movable contact 139 which engages and slides along resistance element 137. Body 136 is pivotally connected to a pin 140 which projects laterally from gear 131 at an eccentric location, while element 138 is connected at an opposite end of unit 87 to a similar pin 141 projecting laterally from gear 132. Pins 140 and 141 are located identical distances from their corresponding axes 133 and 134, and are so positioned as to maintain all positions of linear potentiometer 87 mutually parallel. For this purpose, pin 140 crosses the line 143 between axes 133 and 134 at the same instant that pin 141 crosses that line. Similarly, pins 140 and 141 reach the uppermost point 144 of their travel at the same instant or position of the gears.

'It will be apparent from the above discussion that, if gears 131 and 132 are driven by motor 4M through a suitable drive gear 150, the positioning of movable contact 139 of potentiometer 87 will automatically be in accord ance with two times the cosine of angle A as seen in Fig. 11, if the apparatus is so designed as to maintain that angle exactly equal to angle A of Fig. 8.

At the side of gears 131 and 132 opposite the side at which potentiometer 87 is located, the sine generating second potentiometer 129 is connected to the gears in similar fashion. This potentiometer 129 may be constructed exactly the same as potentiometer 87, but is pivotally attached tothe gears by pins 151 and 152 which are offset about the gear axes from pins and 141 respectively. Consequently, the movable contact of potentiometer 129 is actuated in accordance with two times the sine of angle A rather than its cosine.

As mentioned above, circuit 89 causes the shaft of motor 7M to be positioned or rotated in accordance with the length of line b in Fig. 8. This shaft in mechanically connected to the movable contacts of two potentiometers 154 and 155 in circuit 98, and serves to actuate those movable contacts, and position them in accordance with variations in distance b. Thus, the potential between the positive side of the power source in circuit 90 and the movable contacts of potentiometers 154 and 155 is proportional to the distance b. The resistor elements of potentiometers 154 and 155 are connected in parallel to the power source of circuit 90, and each of these resistor elements is preferably in series with an additional resistor 156 or 157.

The shaft of motor 5M whose positioning is proportional to angle A in Fig. 8 is mechanically connected to a second sine-cosine generator generally represented at 158 in Fig. 13. This second sinecosine generator is essentially the same as that represented at 159 in Fig. 11, and comprises two gear wheels 131a and 132a which are rotatable about parallel axes and mesh together at 142a. The two gear wheels may be mounted in any suitable manner about their individual axes 133a and 13411, as by a number of bearing or bushing elements 160 engaging and journalling relatively large diameter annular bearing surfaces 161 on the gear elements. These bearing surfaces 161 may be of a sufficiently large diameter to 13 avoid interference by the bearings 160 with the various movable parts of the actuated otentiometers and their mountings. The manner of mounting the two gears 131 and 132 has not been shown in Figs. 11 and 12, but may typically be considered to be the same as that shown at 160, 161 in Fig. 13.

The sine-cosine generator of Fig. 13 includes two linear potentiometers 87a and 12%, which are pivotally attached at their opposite ends to gears131a and 13211 by pins 140:: and 141a. These potentiometers are constructed and mounted substantially the same as are the potentiometers 87 and 129 of Figs. 11 and 12, except that the potentiometers 87a and 129m of Fig. 13 are each provided with a center tap 162 in addition to their other leads. The potentiometer 87a is so designed that its movable contact 139a reaches the location of center tap 162 on the potentiometer resistor element exactly when pins 140a and 141a are located either directly above or directly beneath axes 133a and 134a. That is, the center tap is reached when potentiometer 87a is in either its uppermost position or lowermost position. Similarly, the movable contact of potentiometer 12% reaches the point of the center tap on that potentiometer when that potentiometer is in either its uppermost or lowermost position, with the mounting pins of potentiometer 129a in direct vertical alinement with axes 133a and 134a.

When the center tapped potentiometers are mounted in the defined manner, and gears 131a and 132a are driven by motor M to rotary positions corresponding to the angle A in Fig. 8, with the angle A being measured from a line 163 extending directly vertically from one of the axes 133a or 134a in Fig. 13, the settings of potentiometers 87a and 129a are accurately proportional to the cosine and sine respectively of angle A The provision of center taps on the two potentiometers allows the potentiometers to be used for generating the sine and cosine of angle A through the entire 360 rotation of gears 131a and 132a. The resistance between the movable contact of each potentiometer 87a or 12911 and the center tap of that potentiometer represents the cosine or sine of angle A regardless of whether the movable contact of the potentiometer may be to the left or right side of the center tap (as seen in Fig. 13).

The potentiometer 87a of sine-cosine generator 158 is connected into circuit 90 as shown in Fig. 7. Specifically, the center tap 162 is connected to the positive side of the power source, while the two opposite ends of the resistor element of potentiometer 87a are connected respectively to the movable contacts of potentiom eters 154 and 155. Circuit 90 thus forms in effect two multiplier circuits, one of which includes resistor 156,

potentiometer 154, and the lower half of potentiometer 87a (as seen in Fig. 7), and the second of which includes resistor 157, potentiometer 155 and the upper half of potentiometer 87a. The first of these multiplier circuits is effective when the movable contact of potentiometer 87a is above the center tap 162 (in Fig. 7), while the second of the circuits is effective when the movable contact is below the center tap. Together, these two multiplier circuits of the overall circuit 90 act to maintain between the movable contact of potentiometer 87a and center tap 162 a potential which is proportional to b times the cosine of angle A in Fig. 8, and

is therefore proportional to the north-south digression d (which equals b cosine A By virtue of the center tap arrangement of potentiometer 87a, this potential difference gives the north-south digression for any valve of angle A between 0 and 360.

To obtain mechanical movement corresponding to the north-south digression, I employ a read-out potentiometer 164, which is connected across the power source of circuit 90 in series with a resistor 165. The movable contacts of potentiometers 87a and 164 are connected to the input side of amplifier 8, which supplies to motor 8M an amplified potenial corresponding to the difierence in potential between the two movable contacts. Motor 8M acts as a null motor, which serves when energized by a difference in potential between the movable contacts of potentiometers 87a and 164, to mechanically move the movable contact of the latter potentiometer to a position in which there is no difference in potential between the two movable contacts of the potentiometers. Thus, the movable contact of potentiometer 164 is moved in proportion to variations in potential between the movable contact of potentiometer 87a and center tap 162. The shaft of motor 8M also turns to positions which are proportional to the defined potential, so that the positioning of the shaft of motor 8M represents the north-south digression d in Fig. 8. Consequently, the shaft of motor SM is mechanically connected to indicator 25 on board 22, to directly indicate the north-south digression of the bore hole between stations 1 and 2.

The circuit 91 is substantially the same as circuit 90, except that the movable contact of potentiometer 129a of the former circuit is actuated in proportion to the sine of angle A rather than being actuated in accord ance with the cosine as in the case of potentiometer 87a in circuit 90. Consequently, the shaft of read-out motor 9M of circuit 91 is moved in proportion to the eastwest digression e (b sine A2), and therefore causes indicator 24 of board 22 to indicate that east-west digression.

The indicating element 25 on board 22 indicates only the distance d representing the north-south digression in Fig. 8 (typically in feet), but does not indicate whether the digression is toward the north or toward the south. In order to determine whether the digression is to the north or south, I provide an adjacent indicator element 166 alongside indicator 25, having formed on itthe letters N (for north)and S (for south). As seen better in Fig. 13, this element 166 may be positioned behind a window 167 in the wall of board 22, and may be mounted for pivotal movement about an axis 168 between the full line and broken line positions of Fig. 13. The letter N is formed on element 166 at 169, and is visible through window 167 in the full line position of element 166 in Fig. 13, while the letter S is formed at 170, and is visible in the broken line position of element 166. Element 166 has an arcuate portion 171 formed of magnetic metal, which is movable into and serves as the armature of a solenoid 172. When solenoid 172 is energized, it draws element 166 to the full line position of Fig. 13, while element 166 returns to the broken line position under the influence of a spring 173 when coil 172 is deenergized.

The energization of coil 172 by battery 174 is controlled by a switch unit 175. This switch unit comprises a rotatable shaft 176, which is driven by gear 131 of sine-cosine generator 158, in a one to one ratio with that gear, and which carries two electrical contacts 177 and 178 rotatable with shaft 176. These contacts turn to positions representing exactly the angle A Contact 177 is engageable with a semicircular contact 179 as long as contact 177 is in the upper half of its course of circular travel about the axis of shaft 176, that is, as long as the digression of the bore hole between stations 1 and 2 is in a northerly direction. If the digression is to the south, however, the contact between movable contact 177 and semicircular fixed contact 179 is broken. As seen in Fig. 13, the switch formed by contacts 177 and 179 is connected into the energizing circuit of coil 172, to thus cause element 166 to indicate on board 22 whether the digression is toward the north or south.

Adjacent the indicator 24, for representing the distance which the bore hole has digressed in an east-west direction, there is provided an element 180, correspond ing to element 166 but acting to indicate whether the digression is toward the east or west. This element 180 15 is actuated by a solenoid 181, under the control of rotatable contact 178 of device 175. As will be understood, contact 178 engages a semicircular stationary contact 182 when the digression is in an easterly direction, to thus close the energizing circuit to coil 181, but breaks this circuit when the digression is in a westerly direction.

In addition to the parts thus far described, there is provided timer 183, which is of a type to successively and in predetermined timed relation close a number of circuits to the various parts of the apparatus, to thus successively perform different parts of the computing operation of the device. The timer is initially energized by a counter switch 184, which is driven by drum 14-, and acts to close the energizing circuit to timer 183 when drum 14 has been turned through a predetermined number of revolutions (say ten revolutions). This predetermined number of revolutions of course represents a certain predetermined course length through which instrument 11 has been raised or lowered between a pair of stations such as those represented at station 1 and station 2 in Fig 8. When thus energized by counter switch 184, timer 183 commences an automatic cycle of operations, to successively close the following circuits in the following order (after allowing an initial time delay to permit the inner parts of the instrument 11 to come to rest):

(1) Amplifier connected into circuit of Fig. 7 at location amp. 1.

(2) Amplifier connected in at amp. 2.

(3) Amplifier connected in at amp. 3.

(4) Amplifier connected in at amp. 4.

(5 Amplifier connected in at amp. 5.

(6) Amplifier connected in at amp. 6.

(7) Amplifier connected in at amp. 7.

(8) Amplifier connected in at amp. 8.

(9) Amplifier connected in at amp. 9.

(10) Control circuit closed causing camera 26 to pho tograph indicator board 22.

(11) Counter reset motor 185 is energized.

(12) Reel motor 16 is energized to further raise or lower instrument 11 through the distance for which counter switch 184 is set.

To now describe the manner of operation of the apparatus of Figs. 1 through 13, assume first that instrument 11 is suspended on line 12 at the surface of the earth, so that an initial station (station 1 in Fig. 8) is at the earths surface. Also assume that motor 185 has already been energized to drive counter switch 184 in a reverse direction (without of course turning drum 14) so that the counter switch is set in preparation for counting a predetermined number of turns of drum 14. Such resetting of counter switch 184 also serves to reset the movable contacts of the connected potentiometers 127 and 127a of circuits 88 and 89 to zero positions. In the zero positions of potentiometers 127 and 127a, the resistance between the movable contacts of these potentiometers and the positive sides of the power source of the corresponding circuits 88 and 89 is preferably zero.

With the apparatus thus set, an energizing circuit to reel driving motor 16 is closed, to commence lowering of tool 11 into the well. When once closed, this cir cuit to reel motor 16 remains closed until counter switch 184 automatically breaks the circuit after instrument 11 has been lowered through a predetermined distance .a (say about 40 ft.), and to station 2. Upon arrival of the instrument at station 2, counter switch 184 breaks the circuit to reel motor 16, and automatically energizes timer 183. The timer then runs through the cycle of operations listed above. In the first listed timer condition, the single amplifier of the apparatus is connected in at the location amp. 1 of Fig. 7. This causes bridge circuit 74 to become effective and set the shaft tively of Fig. 8.

of motor 1M to a position corresponding to the inclination and therefore resistance of inclination responsive resistor element 17 in the instrument. The timer keeps the amplifier in this circuit 74 for a predetermined period sufiicient to assure actuation of motor 1M to a position representing the inclination of the instrument in the plane of element 17. After the termination of that interval, timer 183 automatically connects the amplifier into circuit 75 at the location amp. 2, to actuate motor 2M to a position representing the inclination of instrument 11 in the plane of resistor element 18. This condition is also maintained for a period sufficient to allow proper reading out of the motor, as are the subsequent conditions to be later described. In the next condition of the apparatus, the amplifier is connected in at amp. 3 so that the shaft of motor SM is actuated to a position proportional to the setting of compass float 4-1 relative to the housing of instrument 11.

Such actuation of motors 1M, 2M and 3M causes resolving device 86 to set potentiometers 117, 118 and 186 to positions representing angles A and A respec- After motors 1M, 2M and 3M have thus been set, the timer connects the amplifier into the circuit of Fig. 7 at the location amp. 4, closing the null balance circuit including read-out potentiometer 123, to thus set motor 4M to a position corresponding to the setting of potentiometer 186 (and therefore angle A Such actuation of motor 4M drives gears 131 and 132 of sine-cosine generator 159 of Figs. 11 and 12 to rotary positions properly representing angle A of Fig. 8. In this setting of the sine-cosine generator potentiometers 87 and 129 are set to positions proportional to two times the cosine and sine respectively of angle A The lowering of instrument 11 within the well to station 2 has of course already preset potentiometers 127 and 127a to positions proportional to the distance through which the instrument has been lowered between stations 1 and 2.

After motor 4M has been caused to follow potentiometer 186, the timer connects the amplifier into the circuit at amp. 5, to actuate the shaft of motor 5M to a position proportional to the setting of potentiometer 116. Thus, motor 5M and the sine-cosine generator 158 driven thereby, are actuated to positions representing angle A of Fig. 8. Next, the timer connects the amplifier at the locations amp. 8 and amp. 9 respectively, to actuate motors 8M and 9M, and their indicator elements 25 and 24, to positions representing distances d and e of Fig. 8. The previously mentioned actuation of sine-cosine generator 158 by motor 5M of course has already preset rotary switch to a condition such that the north-south and east-west indicator elements 166 and are actuated to indicate properly whether the indicated digressions are in a north or south direction, and in an east or west direction. Also, indicator 125 on board 22 is mechanically driven by counter switch 184 to indicate the course length. Subsequent reversal or resetting of counter switch 184 does not, however, drive indicator 125 in a reverse direction, and as a result indicator 125 at all times registers the total course length during a particular run.

The above steps result in setting of all of the indicators on board 22 to properly indicate the vertical depth, the north-south digression, and the east-west digression between stations 1 and 2. At this point, timer 183 closes the circuit to camera 26, to permanently record the data on board 22. The camera control is of course so designed as to automatically advance the film of the camera between successive pictures. Following actuation of camera 26, timer 183 energizes motor 185, to turn counter switch 184 in a reverse direction and to its initial zero position, and to correspondingly actuate the movable contact of potentiometers 127 and 127a to their zero positions. The timer then closes the circuit to reel motor 16, causing it to further lower instrument 11 within the Well and to a third station, at which counter switch 184 again closes the circuit to timer 183 to start another cycle of operation of the computing apparatus. After the apparatus is once set in operation, it will automatically serve to successively lower instrument 11 between a series of different stations, and will stop the instrument at each station long enough for the computing apparatus to run through its cycle of operation and record in camera 26 the condition of indicator board 22 at the particular station. Thus, the apparatus will automatically form a complete survey of the entire Well. The reverse of this procedure may also be following, that is, the instrument may be raised between successive stations in the well, rather than lowered.

Fig. 14 represents a variational form of instrument, which is somewhat like the instrument of Figs. 2a and 2b, except that the Fig. 14 device is responsive to changes in pressure in the well, rather than changes in inclination and rotary position of the instrument. In this Fig. 14 instrument, a multi-turn Bourdon tube type of pressure responsive element 186 is contained within the housing 187 of the device, and is utilized to turn a polarized light passing disc 188 about a vertical axis to positions representing the pressure to which tube 186 is subjected. The polarized disc 188 is substituted in the Fig. 2 apparatus for the polarized disc 49 forming the bottom of the compass float 41. A light source 189 passes light upwardly through disc 188, and through a disc corresponding to that shown at 50 in Fig. 2b, to control photoelectric cells such as those shown at 46 in Fig. 2b in accordance with the passage of light through the polarized discs. The follow-up disc 50, resistor 19, its driving motor 45, mirrors 59 and 61, and the follow-up control circuit of Fig. 6 are all provided in the instrument of Fig. 14, to obtain a reading of potentiometer 19 corresponding to the pressure to which element 186 of Fig. 14 is subjected. All of the parts within housing 187 of Fig. 14 except for pressure responsive element 186 of Fig. 14 may be sealed against contact with the liquid in the well. A horizontal partition 190 within housing 187 may be provided to isolate the upper interior of housing 187 from the well liquid which contacts element 186 in the lower portion of the housing. A shaft extending upwardly from element 186 for turning polarized disc 188 may pass through and be journalled within a suitable opening in partition 190, with a fluid tight seal preferably being formed about this shaft. The lower end 191 of tube 186 is of course anchored against movement relative to housing 187, so that changes in the well fluid pressure communicated to tube 186 causes the shaft at its upper end to turn about a vertical axis.

Fig. 15 shows an additional variational form of the invention which is identical with that of Fig. 14, except that element 192 of Fig. 15 comprises a bimetallic metal strip, which responds to well fluid temperature, rather than pressure, so that the polarized disc and following resistor element are also positioned in accordance with the temperature within the well.

It will of course be understood that the various electrical components of the Figs. 6 and 7 circuits may be given any of numerous values, as long as the overall circuits are capable of functioning in the defined manner.

However, for the sake of completeness of the disclosure, I will list certain typical values which these components may have in a preferred form of the apparatus:

Battery 67 6 volts.

Voltage dividers 197 and 198..- 2000 ohms.

Resistors 199 and 200 10 megohms.

Transformer 64 Primary 120 volts; secondary 6.3 volts.

Transformer 201 Output matched to motor 45.

Resistors 17 and 18 10,000 ohms.

Resistor 19 5000 ohms.

Resistors 78 and 78a 1200 ohms. Resistors 79, 79a and 79b 500 ohms. Resistors 80 and 80a 600 ohms. Resistors 81 and 81a 1100 ohms. Resistor 78b 5000 ohms.

Resistor 80b 2500 ohms. Resistor 81b 3000 ohms.

Potentiometers 117 and 20,000 ohms. Potentiometers 106 and 123 5000 ohms.

Battery 122 6 volts. Battery 126 6 volts. Potentiometers 127, 127a, 154,

155, 154a and 155a 2000 ohms. Resistors 128, 128a, 156, 157,

156a and 157a 2000 ohms.

Potentiometers 87 and 129 400,000 ohms. Potentiometers 87a and 12%.. 400,000 ohms at each side of the center tap. Potentiometers 153, 153a, 164

and 164a 5000 ohms. Resistors 130, 130a, 165 and 165a 5000 ohms.

All of the potentiometers utilized in this apparatus preferably have linear windings.

It is contemplated that the sine-cosine generator or resolver shown in Fig. 11 may be utilized in various other types of apparatus in which it is desired to generate a representation of a trigonometric function of an angle. When thus used, there may be substituted for the potentiometers 87 and 129a any other suitable type of transducer, as for instance a differential transformer, whose output may be controlled by the resolver in accordance with the trigonometric function. i

I claim:

1. Apparatus comprising an instrument body adapted to be lowered into a well bore at the lower end of a sus-. pending line and to be advanced along the bore, means at the surface of the earth adapted to be actuated in accordance with the advancement of said line to thereby be responsive to the course length through which said instrument body is advanced along the bore between two stations, second means responsive to the inclination of said instrument body in the bore, and computer means responsive to both said first and second means and operable at the surface of the earth adapted to be actuated. in

accordance with the advancement of said line to thereby be responsive to the course length through which said instrument body is advanced along the bore between two stations, second means responsive to the inclination of said instrument body in the bore, and computer means responsive to both said first and second means and operable to develop representations 'of the vertical distance between the levels of said two stations and also the horizontal digression between said two. stations in two mutually perpendicular directions.

3. Apparatus comprising an instrument lbody adapted to be lowered into a well bore at the lower end of a1 suspending line and to be advanced along the bore, means at the surface of the earth adapted to be actuated in accordance with the advancement of said line to thereby .be responsive to the course length through which said instrument body is advanced along the bore between two! stations, second means responsive to the inclination of said instrument body in the bore, third means responsive to the rotary positioning of said inclination responsive means in the well to orient the same, and computing meansresponsive to said first, second and third means and operable to produce representations of the vertical 19 depth between .said stations and the north-south and eastwest digression of said bore between said stations.

4. Apparatus comprising an instrument adapted to be lowered into and advanced along a well bore, first means responsive to the course length through which said instrument is advanced along the bore between two stations, second means responsive to the inclination of said instrument in the bore, third means responsive to the rotary positioning of said inclination responsive means in the well to orient the same, computing means responsive to said first and second means and acting to multiply said course length by two different trigonometric functions of the true angle of inclination with respect to a true vertical line to arrive at vertical and horizontal components of the course length, and additional computing means responsive to said last mentioned means and said third means and acting to multiply said horizontal component by trigonometric functions of an angle representing the compass direction of said inclination to arrive at the northsouth and east-west digression of said bore.

5. Apparatus comprising a well surveying instrument adapted to be lowered into and advanced along a well bore, means for advancing said instrument between successive stations in the well, means operating to record survey information obtained by said instrument, and automatic timing means for operating said advancing and recording means in predetermined timed relation to advance said instrument from one station to another, then stop the advancement and make a record of said survey information at that station, then advance the in strument to the next station, and then make a record of the survey information at said next station.

.6. Apparatus comprising a well surveying instrument adapted to be lowered into and advanced along a well bore, means for advancing said instrument between successivestations in the well, computing means operating to compute vertical and horizontal components of the course length between successive stations, and automatic timing means for operating said advancing and computing means in predetermined timed relation to advance said instrument from one station to another, then stop the advancement and compute said components of the course length between said stations then advance the instrument to the next station, and then compute said components of the second course of advancement.

7. A well surveying apparatus comprising an instrument body adapted to be lowered into a well bore at the lower end .of a suspending line and to be advanced along the well bore, means at the surface of the earth adapted to be actuated in accordance with the advancement of said line to thereby be responsive to the course length through which said body is advanced along the bore between two stations, inclination responsive means operable to vary a controlled signal in accordance with the true inclination of said body in the bore with respect to a true vertical line, and computer means responsive to said first mentioned means and to said inclination responsive means and'operable to combine said course length and said true inclination to arrive at a representation of a component of said course length.

8. Apparatus as recited in claim 7 in which said computer means comprise means acting to multiply said course length by a trigonometric function of said true inclination to arrive at said component.

9. Apparatus as recited in claim 7 in which said computer means comprise atrigonometric resolver acting to develop a representation of a trigonometric function of said true angle of inclination, and a multiplier circuit actingto multiply said function by said course length to develop said component of the latter.

- 10. Apparatus as recited in claim 7 in which said computermeans comprisesine-cosine resolving means acting to develop electrical representations of the sine and cosine of said actual angle of inclination of the body, and multiplier circuits for separately multiplying said course length by said sine and cosine to arrive at vertical and horizontal. components of said course length.

11. Apparatus comprising an instrument adapted to be lowered into and advanced along a well bore, first means responsive to the course length through which said instrument is advanced along the bore between two stations, second means responsive to the inclination of said instrument in the bore, third means responsive to the rotary positioning of said inclination responsive means in the well to orient the same, and computing means re sponsive to said first, second and third means and operable to produce representations of the vertical depth between said stations and the north-south and east-west digressions of said bore between said stations, said computing means comprising means multiplying said course length by two different trigonometric functions of the angle of inclination to obtain the horizontal digression and the vertical digression of the bore, and additional means multiplying said horizontal digression separately by the sine and cosine of an angle representing the compass direction of the inclination to obtain said north-south and east-west digressions.

12. Well surveying apparatus comprising an instrument body to be lowered into a well bore at the lower end of a suspending line and to be advanced between two stations in the bore, first and second inclination responsive means operable in accordance with two difierent components respectively of the true inclination of said body with respect to a true vertical line, resolver means operable to combine said two inclination components and to vary an output signal in accordance with said true inclinations, means at the surface of the earth adapted to be actuated in accordance with the advancement of said suspending line and to thereby be responsive to the course length through which said instrument is advanced between said two stations, and computer means responsive to said signal representing the actual inclination and to said course length as developed by said last mentioned means and operable to develop therefrom a representation of a component of said course length.

13. Apparatus as recited in claim 12 in which said developed component is the vertical distance between said two stations.

14. Apparatus as recited in claim 12 in which said computing means comprise means acting to multiply said course length by a trigonometric function of said true inclination.

15. A well surveying apparatus comprising an instrument body adapted to be lowered into and advanced along a well bore, first means responsive to the course length through which said body is advanced along the bore between two stations, inclination responsive means operable to vary a controlled signal in accordance with the true inclination of said body in the bore with respect to a true vertical line, additional means responsive to the rotary positioning of said inclination responsive means in the well, and computer means including sine-cosine resolving means acting to develop electrical representations of the sine and cosine of said actual angle of inclination of the body, multiplier circuits for separately multiplying said course length by said sine and cosine to arrive at vertical and horizontal components of said course length, second sine-cosine resolving means responsive to said additional means and acting to develop electrical representations of the sine and cosine of an angle representing the compass direction of the inclination, and multiplier circuits for separately multiplying said horizontal digression by said last mentioned sine and cosine to arrive at the north-south and east-west digressions of said bore.

16. Well surveying apparatus comprising an instrument body to be lowered into a well bore and advanced between two stations in the bore, first and second inclination responsive means operable in accordance with two difierent components respectively of the true inclination of said body' with respect to a true vertical line, resolver means operable to combine said two inclination components and to vary an output signal in accordance with said true inclinations, means responsive to the course length through which said instrument is advanced between said two stations, computer means responsive to said signal representing the actual inclination and to said course length as developed by said last mentioned means and operable to develop therefrom a representation of a component of said course length, said computing means comprising a sine-cosine generator for developing the sine and cosine of said true inclination, and multiplier circuits for multiplying said course length by said sine and cosine to arrive at the vertical and horizontal components of said course length, said apparatus including compass means responsive to the rotary positioning of said two units for producing a representation of the compass direction of said inclination, a second sine-cosine generator responsive to said compass means and acting to develop the sine and cosine of an angle representing said direction of inclination, and multiplier circuits for multiplying said horizontal component of the course length by said last mentioned sine and cosine separately to arrive at the north-south and east-west digression of the bore hole.

17. Well surveying apparatus comprising an instrument body to be lowered into a well bore and advanced between two stations in the bore, first and second inclination responsive means operable in accordance with two different components respectively of the true inclination of said body with respect to a true vertical line, resolver means operable to combine said two inclination components and to vary an output signal in accordance with said true inclinations, means responsive to the course length through which said instrument is advanced between said two stations, computer means responsive to said signal representing the actual inclination and to said course length as developed by said last mentioned means and operable to develop therefrom a representation of a component of said course length, said resolving means including two screw and nut assemblies extending in two essentially perpendicular directions, an element actuable in said two directions by said screw and nut assemblies respectively, means for actuating said assemblies in accordance with said two components of the bore inclination so that the positioning of said element represents the true inclination, a first potentiometer re sponsive to the distance of said element from a predetermined center and thereby representing the true inclination, and a second potentiometer responsive to the rotary positioning of said element about said center and representing the direction of said inclination, said computer means being responsive to both of said potentiometers and operable to develop horizontal and vertical components of the course length from said true inclination and said direction of the inclination.

18. Apparatus as recited in claim 17 in which said second potentiometer includes relatively rotatable resistor and contact sections, said apparatus including means for rotating one of said sections in accordance with the movement of said element about said center, and means for rotating the other section in accordance with the rotary positioning of said first and second inclination responsive means in the well so that the setting of said second potentiometer represents the compass direction of the true inclination.

19. Well surveying apparatus comprising an instrument body to be lowered into a well bore and advanced between two stations in the bore, first and second inclination responsive means operable in accordance with two difierent components respectively of the true inclination of said body with respect to a true vertical line, resolver means operable to combine said two inclination components and to vary an output signal in accordance with said true inclinations, means responsive to the course length through which said instrument is advanced between said two stations, computer means responsive to said signal representing the actual inclination and to said course length as developed by said last mentioned means and operable to develop therefrom a representation of a component of said course length, said resolving means including two screw and nut assemblies extending in two essentially perpendicular directions, an element actuable in said two directions by said screw and nut assemblies respectively, means for actuating said assemblies in accordance with said two components of the bore inclination so that the positioning of said element represents the true inclination, and means operable to vary in accordance with the distance of said element from a predetermined center to thereby represent said true inclination, said computer means being responsive to said electrical signal.

20. Well surveying apparatus comprising an instrument body to be lowered into a well bore and advanced between two stations in the bore, first and second inclination responsive means operable in accordance with two different components respectively of the true. inclination of said body with respect to a true vertical line, resolver means operable to combine said two inclination components and to vary an output signal in accordance with said true inclinations, means responsive to the course length through which said instrument is advanced between said two stations, computer means responsive to said signal representing the actual inclination and to said course length as developed by said last mentioned means and operable to develop therefrom a representation of a component of said course length, said resolving means including two screw and nut assemblies extending in two essentially perpendicular directions, an element actuable in said two directions by said screw and nut assemblies respectively, means for actuating said assemblies in accordance with said two components of the bore inclination so that the positioning of said element represents the true inclination, and means responsive to the rotary positioning of said element about said center and operable to vary an electrical signal in accordance with the compass direction of said inclination, said computer means being responsive to said electrical signal.

21. Well surveying apparatus comprising an instrument body to be lowered into a well bore and advanced between two stations in the bore, first and second inclination responsive means operable in accordance with two ditferent components respectively of the true inclination of said body with respect to a true vertical line, resolver means operable to combine said two inclination components and to vary an output signal in accordance with said true inclinations, means responsive to the course length through which said instrument is advanced between said two stations, computer means responsive to said signal representing the actual inclination and to said course length as developed by said last mentioned means and operable to develop therefrom a representation of a component of said course length, said resolving means including two screw and nut assemblies extending in two essentially perpendicular directions, an element actuable in said two directions by said screw and nut assemblies respectively, means for actuating said assemblies in accordance with said two components of the bore inclination so that the positioning of said element represents the true inclination, a potentiometer having relatively rotatable resistor and contact sections, means for rotating one of said sections in accordance with movement of said element about said center, and means for rotating the other section in accordance with the rotary positioning of said first and second inclination responsive means in the well, said computer means being responsive to the setting of said potentiometer.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS AuschutZ-Kaempfe Dec. 19, 1916 Jackson Mar. 7, 1939 Berry July 25, 1939 Potapenko Feb. 20, 1940 Fischel Oct. 29, 1940 Moseley Nov. 11, 1941 

